A variety of operations require the use of a catheter to deliver irrigation to a surgical site. For example, treatment of cardiac arrhythmias often require locating in the heart the sites of origin of the arrhythmia or sites of abnormal conduction, and ablating these sites through delivery of radiofrequency energy through an electrode located at or near the tip of a catheter. However, if the temperature of the electrode and/or temperature of the immediately surrounding tissue become excessively high during such a procedure, the patient may suffer adverse consequences. In particular there is a risk of charring of the tissue in contact with the electrode, creating steam pops in the tissue and coagulating the surrounding blood. These undesired effects may lead to excess damage to the tissue compromising its physical integrity which could be catastrophic for the patient and/or increasing the risk of the patient suffering a stroke as a result of coagulated blood or tissue fragments propagating through the blood stream to the patient's brain. It can be desirable to attempt to reduce the risk of such undesirable effects by cooling the electrode and the tissue immediately surrounding the electrode by delivering irrigation fluid through or around the electrode. The irrigation fluid may exit through the electrode into the region immediately surrounding the electrode. However, effectively delivering such irrigation to a remote tissue site within the human body can present challenges.
Accordingly, there remains a need for catheters having improved irrigation and ablation abilities.